Ch. XIII] 



TEETH OF FOSSIL QUADRUPEDS. 



165 



tombed in superficial deposits. These genera comprehended many spe- 

 cies, some of which were 4, some 7, others 9, and others 11 feet in 

 height ! It seems doubtful whether any contemporary mammalia shared 

 the land with this population of gigantic feathered bipeds. 



To those who have never studied comparative anatomy it may seem 

 scarcely credible, that a single bone taken from any part of the skeleton 

 may enable a skilful osteologist to distinguish, in many cases, the genus, 

 and sometimes the species, of quadruped to which it belonged. Although 

 few geologists can aspire to such knowledge, which must be the result of 

 long practice and study, they will nevertheless derive great advantage 

 from learning what is comparatively an easy task, to distinguish the 

 principal divisions of the mammalia by the forms and characters of their 

 teeth. The annexed figures, all taken from original specimens, may be 

 useful in assisting the student to recognize the teeth of many genera most 

 frequently found fossil in the Newer Pliocene and Post-Pliocene periods : — 



Fig. 134. 



Elephas primigeniiirS (or Mammoth) ; molar of upper jaw, right side ; one-third of nat. sizo, 

 a. Grinding surface. 6. Side view. 



Fig. 135. 



Mastodon arcernensin (Norwich Crag, Postwick, also found in Eed Crag, see p- 155); second 

 true molar, left side, upper jaw ; grinding surface, nat. size. (See. p. 155.) 



